This invention relates broadly to fluid flowmeters and is particularly concerned with a novel swirler for a flowmeter and a method of making the same.
U.S. Pat. No. 3,616,693 discloses a swirl-type flowmeter containing a swirler of the general type to which the present invention relates. In order to impart the desired swirl to the fluid passing through the flowmeter, immediately adjacent blades of the swirler must be both axially and circumferentially overlapping. While the disclosure of this prior patent fails to address itself to the manner of fabricating the swirler, the drawings thereof suggest that the blades are individually fabricated and then joined to an outer ring which is in turn inserted onto a central hub with each of the blades lodging in a corresponding axial groove in the hub.
The present invention is directed to an improvement in the foregoing type of swirler and relates both to the article per se and to the method of its manufacture. An outstanding attribute of the present invention is that the cost of making such a swirler is dramatically reduced. This is because the swirler can be made from two molded plastic parts which are subsequently assembled together. Furthermore, each of the two molded plastic parts can be made by means of simple molding dies. Thus, the invention makes the mass production fabrication of a fluid flowmeter embodying a swirler of this type economically feasible.
The accompanying drawings disclose a preferred embodiment of the present invention according to the best mode presently contemplated in carrying out the invention.